Operating method and system for supporting lane keeping of a vehicle

Abstract

A system and an operating method are provided for supporting lane keeping of a vehicle equipped with a steering device. The system and operating method include providing vehicle related information; providing environment related information; combining vehicle and environment related information; predicting a future trajectory of the vehicle based on vehicle and environment related information; estimating a desired lateral lane position of the vehicle and/or a guiding force; comparing the future trajectory and the desired lateral lane position; deciding if a guiding force is to be provided to the steering device; and, if guiding force is to be provided, defining an amount of said guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, adapting the amount of guiding force depending on the direction in which the vehicle is intended to move and activating one or more actuators for supplying the adapted amount of guiding force to the steering device.

The invention claimed is: 
     
       1. An operating method for supporting lane keeping of a vehicle equipped with a steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 detecting whether a force is exerted on the steering device by a driver; 
 providing a guiding force to the steering device when the force is exerted on the steering device by the driver; and when providing the guiding force, 
 a) defining an amount of the guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and 
 c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device. 
 
     
     
       2. The method according to  claim 1 , wherein the-predetermined driving behavior is prioritized in the order of
 stabilizing the vehicle; 
 preventing the vehicle from leaving the lane; 
 supporting the turning of the vehicle when travelling a curved trajectory along a bend. 
 
     
     
       3. The method according to  claim 1 , comprising using at least one of a lateral displacement, a lateral velocity, a lateral acceleration of the vehicle and a curvature of the road as input variables of the predetermined driving behavior. 
     
     
       4. The method according to  claim 1 , comprising determining the amount of guiding force by at least one of an expert system, artificial intelligence system, fuzzy logic system. 
     
     
       5. The method according to  claim 1 , wherein for driving on a straight road the guiding force is adapted to increase if the lateral velocity of the vehicle increases when the vehicle is laterally moving away from the desired lateral position. 
     
     
       6. The method according to  claim 1 , wherein for driving on a straight road the guiding force is adapted according to desired driving conditions and/or a desired state of the vehicle. 
     
     
       7. The method according to  claim 1 , wherein when moving towards a desired lateral position the guiding force is negative if the actual lateral velocity is below the actual desired lateral velocity, positive if the actual lateral velocity is above the actual desired lateral velocity, and zero if the actual lateral velocity is equal or almost equal to the actual desired lateral velocity. 
     
     
       8. The method according to  claim 1 , wherein when moving towards a desired lateral position the desired lateral velocity is at least a function of time and/or lateral deviation from the desired lateral position and/or curvature of the road or lane. 
     
     
       9. The method according to  claim 8 , wherein the desired lateral velocity is a function with a maximum and two inflection points on each side of the maximum, the inflection points preferably each having a value equal to or almost equal to zero. 
     
     
       10. The method according to  claim 1 , wherein the guiding force increases or decreases a resistance of the steering device counteracting the force exerted by the driver onto the steering device. 
     
     
       11. The method according to  claim 1 , wherein the guiding force always counteracts the actions of the driver when moving the vehicle away from a desired position and/or a desired state of the vehicle. 
     
     
       12. The method according to  claim 1 , wherein the guiding force is triggered only when moving the vehicle away from a desired position and/or a desired state of the vehicle. 
     
     
       13. The method according to  claim 1 , wherein for travelling a curved trajectory along a bend the guiding force towards an inside of the bend is different to the guiding force towards an outside of the bend. 
     
     
       14. The method according to  claim 13 , wherein for travelling a curved trajectory along a bend the guiding force towards an inside of the bend is adapted to be greater than for an equivalent situation on a straight road. 
     
     
       15. The method according to  claim 13 , wherein for following a curved trajectory along a bend the guiding force towards an outside of the bend is adapted to be lower than for an equivalent, situation on a straight road. 
     
     
       16. The method according to  claim 1 , comprising providing object data fusion and lane data fusion for environment related information. 
     
     
       17. The method according to  claim 1 , comprising providing at least one of wheel speed data, yaw rate data and steering wheel angle data as vehicle related information. 
     
     
       18. The method according to  claim 1 , wherein the lane keeping support system and/or a lane departure warning system is/are disabled when, and during the period of time, the vehicle is intentionally moved away from the desired lateral position. 
     
     
       19. An operating method for supporting lane keeping of a vehicle equipped with a steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 providing a guiding force to the steering device; and when guiding force is provided,
 a) defining an amount of the guiding force depending on a hierarchically ordered set describing, a predetermined driving behavior of the vehicle, 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and 
 c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device, 
 
 wherein with a trailer attached to the vehicle, the desired lateral position for the vehicle following a curved trajectory along, a bend is estimated dependent on the desired lateral position of the trailer. 
 
     
     
       20. The method according to  claim 19 , wherein the desired lateral position of the vehicle is shifted towards an outside of the bend compared to the lateral position of the trailer. 
     
     
       21. The method according to  claim 19 , wherein the lane keeping support system and/or a lane departure warning system is/are disabled when, and during the period of time, the vehicle is leaving the lane on the outside if the trailer is predicted to stay at, or leave the lane on, the inside of the bend. 
     
     
       22. An operating method for supporting lane keeping of a vehicle equipped with a steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 providing a adding force to the steering device; and when guiding force is provided,
 a) defining an amount of the guiding force depending, on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and 
 c) activating one or more actuators for supplying; the adapted amount of guiding force to the steering device, 
 
 
       wherein guiding force is provided depending on a classification of the road. 
     
     
       23. The method according to  claim 22 , wherein in case the probability that an adjacent lane exists exceeds a predefined threshold and it is decided to provide a guiding force to prevent a lane departure in that direction, the guiding force is chosen to be lower than in case no adjacent lane is present. 
     
     
       24. The method according to  claim 22 , wherein at a road border with no adjacent lane the guiding force is higher in direction of the road border. 
     
     
       25. An operating method for supporting, lane keeping of a vehicle equipped with a steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 providing a guiding force to the steering device; and when guiding force is provided,
 a) defining an amount of the guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and 
 c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device, 
 
 wherein in case of a lane departure when travelling along a bend in lateral direction towards the road centre, a guiding force is determined according to traffic conditions. 
 
     
     
       26. The method according to  claim 25 , wherein the guiding force is provided depending on expected oncoming traffic. 
     
     
       27. The method according to  claim 25 , wherein the guiding force is provided depending on expected overtaking traffic. 
     
     
       28. An operating method for supporting lane keeping of a vehicle equipped with a steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 providing a guiding force to the steering device; and when guiding force is provided,
 a) defining an amount of the guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, 
 b) adapting die amount of guiding, force depending on the direction in which the vehicle is intended to move, and 
 c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device, 
 
 wherein a lane departure warning and/or a guiding force is enabled when the predicted time to a lane departure is less than a variable threshold. 
 
     
     
       29. The method according to  claim 28 , wherein the variable threshold is a function of the magnitude of the lateral velocity of the vehicle, and the variable threshold preferably increases with increasing lateral velocity of the vehicle. 
     
     
       30. A lane keeping system of a vehicle equipped with a steering device, comprising
 a support unit comprising a data fusion module for producing environment related information, 
 a trajectory predictor module for predicting a future trajectory of the vehicle, 
 an estimator module for estimating a desired lateral lane position of the vehicle and/or a guiding force, and 
 a decision system module for detecting whether a force is exerted on the steering device by a driver and, if the force is exerted on the steering device by the driver, deciding if a guiding force should be provided and, if to be provided, for defining an amount of such guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, and adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and activating one or more actuators for supplying the adapted amount of guiding force to the steering device, with one or more inputs for sensor data for the data fusion module, an input for vehicle related data and one or more outputs for an output of guiding force demand and/or warning signal. 
 
     
     
       31. The system of  claim 30 , comprising an electric motor for providing a guiding force to a steering device. 
     
     
       32. A non-transitory computer readable medium comprising a software code adapted to perform a method or for use in a method for supporting lane keeping of a vehicle equipped with as steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 detecting whether a force is exerted on the steering device by a driver; 
 if the force is exerted on the steering device by the driver, providing a guiding force to the steering device; and 
 when guiding force is provided,
 a) defining an amount of the guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and 
 
 
       c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device. 
     
     
       33. A computer programmed with software code for use in a method for supporting keeping of a vehicle equipped with a steering device, comprising
 providing vehicle related information; 
 providing environment related information; 
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position of the vehicle and/or a guiding force; 
 comparing the future trajectory and-the-desired lateral lane position; 
 detecting whether a force is exerted on the steering device by a driver; 
 if the force is exerted on the steering device by the driver, providing a guiding force to the steering device; and 
 when guiding force is provide,
 a) defining an amount of the guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and 
 c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device. 
 
 
     
     
       34. A non-transitory computer readable medium comprising a computer program product, the computer readable program product comprising a program code for use in a method comprising at least the steps of
 combining vehicle and environment related information; 
 predicting a future trajectory of the vehicle based on vehicle and environment related information; 
 estimating a desired lateral lane position and/or a guiding force; 
 comparing the future trajectory and the desired lateral lane position; 
 detecting whether a force is exerted on the steering device by a driver; 
 if the force is exerted on the steering device by the driver, providing a guiding force to the steering device; and 
 when guiding force is to be provided,
 a) defining an amount of the guiding force depending-on a hierarchically ordered set describing a predetermined driving behavior of the vehicle; 
 b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move. 
 
 
     
     
       35. The computer readable medium according to  claim 34 , wherein the method further comprises the step of activating one or more actuators for supplying the adapted amount of guiding force to the steering device.